Key-socket or switch for incandescent electric lamps



(No Model.)

A. B. HOLMES & G. P. GALE.

KEY SOCKET 011 SWITCH FOR INGANDBSGENT ELEOTRIO LAMPS. N0. 427.51 Patented May 6, 1890.v

7- E5: I 455% M.

UNITED "STATES PATENT OFFICE.

ARNOLD B. HOLMES, OF BOS'lON, AND GEORGE F. GALE, OF \VINTHROP,

MASSACHUSETTS.

KEY-SOCKET OR SWITCH FOR INCANDESCENT ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 427,514, dated May 6, 1890. Application filed October 2d, 1839. Serial No. 328,010. (No model.)

T 00% whom it may concern.-

Be it known that we, ARNOLD B. HOLMES, of Boston, in the county of Suffolk and State of Massachusetts, and GEORGE F. GALE, of \Vinthrop, in the county of Suffolk and State of Massachusetts, have invented certain. new and useful Improvements in Key-Sockets or Switches for Incandescent Electric Lamps, of which the following is a description sufliciently full, clear, and exact to enable any person skilled in the art or science to which said invention appertains to make and use the same, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 is a side elevation of ourimproved key-socket detached from the lamp; Fig. 2, an end elevation of the same, showing the position of the key when the circuit is closed; Fig. 3, a like view showing the position of the key when the circuit is broken; Fig. 4, a vertical transverse section shown 011 line 09 0c in Fig. 3.

Like letters and figures of reference indicate corresponding parts in the different urcs of the drawings.

Our invention relates especially to keysockets'for breaking and closing the electric circuit in incandescentlamps; and it consists in certain novel features hereinafter fully set forth and claimed, theobject being to produce a simpler, cheaper, and more effective device of this character than is now in ordinary use.

The nature and operation of the improvement will be readily understood by all con- Versant with such matters from the following explanation.

In the drawings, A represents the body of the socket, which consists, primarily, of a re ctangular metallic post or rod screw-threaded at both ends, as best shown in Fig. 4.

A disk I), composed of hard rubber, is turned onto the end 61 and secured in position by a key f. A segmental disk g, also composed of hard rubber, is turned onto the opposite end h of said body and secured thereto by a key 1, thethreaded end h of the body projecting a sufiicient distance beyond said disk to receive the lamp.

A strip of metal on, preferably phosphor bronze, is secured to the inner face of the disk Z), its free end 13 being bent downward toward the disk g at an angle to the disk Z). A similar-strip of phosphor-bronze qis secured to the outer face of the disk g, a free end 4 thereof being bent upward past the straight edge 25 of the disk 9 and parallel with the free end 19 of the strip on.

A horizontally-arran ged rubber tube 41 passes centrally through the body A. A key D is fitted to rotate in said tube and is'provided on one end with a thumb-piece w.

A rectangular metallic holder .2 is disposed loosely on the opposite end of the shaft of the key 1).

A rectangularblock y of insulating material, preferably hard rubber, is secured in the holder around the key-shaft D by pin j. A pin 15 on thekey-shaft works loosely in a slot or groove 16 in said block. 011 opposite sides two edges 17 of the holder .2 are turned upward over the sides of the block y in position to come into contact with the free ends T1) of the strips m g, said block and holderbeing disposed on the key-shaft between said strips.

A metallic connector 18 is secured to the disk Z) in contact with the bronze strip on, and is provided in its lower end with a set-screw 19. A similar connector 20, provided with a set-screw 21, is secured to the body A at the side opposite the connector 18.

In the use of our improvement the lamp is turned on the threaded end h of the body A until its filament comes into contact with the strip q. The conducting-wires are respectively secured in contact with the connectors 18 and 20 by threaded screws 19 and 21.

Nhen the parts are in the position shown in Fig. 2, the metallic sides 17 of the holder .2

are in contact with the free ends p r of the strips m g, and the circuit is closed through the wires.

By turning the key D a qualter-revolution its pin 15, engaging the wall of the slot 16, forces and revolves said holder a corresponding distance, and the ends of the insulatingblock y are brought into contact with the strip ends 1' p, the circuit being thus broken. (See Fig. 3.) The ends 4' p, being composed of spring metal, bear against the sides of the holder or insulating-block suiiicientlyhard to prevent them from being accidentally tu rned. By means of {the pin and slot 16 sufficient play is aiforded to enable the spring ends of the strips m g to act upon the holder and complete a quarter-revolution should the key accidentally not be turned sufficiently far to effect this and prevent an are being formed.

The holder 2' and block y form a rectangular cam H for closing and breaking the circuit between the electrodes formed by the bronze strips m q.'

The plate (1 and body A form the lamp terminals.

Having thus explained our invention, what we claim is 1. The combination of a short metallic center post provided with an insulating-disk at its upper end and with an insulating segmental disk at its lower end, said post having a screw-threaded extension below the lower disk for receiving a lamp, a spring-electrode attached at one end to the upper disk and provided with a downwardly extending springarm, a metallic plate attached to the lower face of the segmental disk and provided with a spring arm extending upward past the straight side of said disk, an insulating-sleeve extending transversely through said center post for a rotary key within said sleeve pro- Vided at one end with a rectangular cain disposed between said spring-arms, said cam having conductors on two opposite sides.

2. The combination of a short metallic center post provided with an insulating-disk at its upper end and wit-h an insulating segmental disk at its lower end, said post having a screwthreaded extension below the lower disk for receiving a lamp, a binding-post dependent from the lower face of the upper disk, a binding-post attached to said center post, a spring-electrode attached at one end to the up er disk in contact with the dependent binding-post and providedwith a downwardlyextending springarm, a metallic plate attached to the lower face of the segmental disk an d provided with a spring-arm extending upward past the straight side of said disk, an insulating sleeve extending transversely through said center post, and a rotary key 7 within said sleeve provided at one end with a rectangular cam disposed between said 

